DM Flashcards
What is DM
Chronic condition characterised by abnormal high BG
Why is managing DM important
Prevent microvascular - eye / kidney / nerve complications
Prevent macrovascular - IHD / stroke complications
What are the types of DM
Type 1 Type 2 Gestational MODY Other
What causes type 1
Autoimmune attack on beta cells so destroyed
Results in absolute deficiency of insulin
Genetic + trigger
Associated with other autoimmune conditions
What Ab associated
GAD Ab
How and when does type 1 present
Childhood
Symptomatic or acutely unwell e.g. DKA
Prone to DKA and weight loss
What does type 1 require
Daily insulin or will be fatal
SC or IV
Can’t take oral as will be broken down by gut
What causes type II
Deficiency in insulin due to express adipose insensitivity and pancreas not able to produce enough
B cells normal and may even have hyper insulin
What causes insensitivity
Obesity = increased Fa decreasing insulin sensitivity
If pancreas can’t secrete enough to meet demand will become diabetic
What is the genetic component of type II
Whether pancreas can secrete higher levels
NOT adipose genes or HLA
What is associated with type II
Obesity - central adiposity (reversible) FH Age Ethnicity - south Asian / black Gestational Inactivity
What is MODY
AD genetic disorder affecting B cells and production
Glucokinase / transcription factor mutation
How does MODY tend to present
Younger patient <25
Symptoms similar to type II
DKA not a feature
FH of early onset
What drugs are MODY patient sensitive to
Sulphonylurea - gligliazide
What are other causes of DM
Chronic pancreatitis Haemochromotosis CF Drugs - glucocorticoid Cushing's Acromegaly Phaeochromocytoma Hyperthyroid Pregnancy
How does type 1 present
Polyuria - water dragged out with glucose
Polydipsia
Weight loss
Fatigue
Blurred vision - glucose builds up in from of lens
Thrush / recurrent infection - oral candidiasis
Slow wound healing
DKA
How does type II present
Incidental on bloods Same symptoms as type I Can present with complications Often overweight No ketones
What is needed to diagnose DM
Symptoms + 1+ or 2+ of Blood glucose fasted >7 Random BG >11.1 OGTT >11.1 HbA1c >48
What is OGTT
Take 75g CHO
Take BG before and 2 hours after
What is HbA1c
Tool used to measure long term control
Shows average BG over 3 month period
Dependent on RBC lifespan and average BG
How often should you check
Every 3-6 months until stable then 6 monthly
What causes reduced levels as reduced life span of RBC
Sickle cell
G6PD
Hereditary spherocytosis
Haemolytic anaemia
What causes higher levels as increased RBC lifespan
Vit B12 / folic deficiency
Iron deficiency
Splenectomy
When can HbA1c not be used as diagnostic tool
Type 1 Children Pregnancy If short duration of Sx Acutely ill CKD HIV People on meds that may cause hyperglycaemia - steroid / anti-psychotic Acute pancreatic damage Anaemia's / haemoglobinopathy
What is pre-diabetic
Impaired glucose fasting
Impaired glucose tolerance
What causes
IGF due to hepatic resistance
IGT due to muscle resistance
What happens if discovered to be pre-diabetic
Surveillance as high risk of type II
Lifestyle measure
Yearly follow up
What are blood test levels of pre-diabetic range
HbA1c 6.1-7
Fasting BG 6.1-7
OGTT >7.8 but <11.1
How do you treat DM
Normalise BG with lifestyle or drugs
Monitor and Rx complications - annual foot, eye and kidney screen
Modify CVS RF - cholesterol / BP
When investigating DM what other tests can be done
FBC U+E - osmotic Sx / dehydration Bicarb - if high suggests acidosis Liver function - DM 2 to NAFLD Test for coeliac in all newly Dx type 1 TFT - common in type II GAD Ab
How do you monitor DM
HbA1c every 3-6 months
Capillary blood glucose
What is an insulinoma and how does it occur
Benign pancreatic islet tumour
Sporadic
Associated with MEN 1
How does it present
Fasting hypo with Whipples triad
What is Whipples
Symptoms associated with fasting or exercise
Recorded hypo with Sx
Symptoms relived with glucose
How do you screen
Hypoglycaemia with increased plasma insulin
What suppressive test can be done
Give IV insulin and measure C-peptide
Normally exogenous insulin will suppress C-peptide but this does not occur
How do you image
CT / MRI with pancreatic USS
How do you Rx
Excision
How do you differentiate from type 1 and type 2
C-PEPTIDE
Low in type 1 as no insulin produced to brea down
Normal or high in type 2
